Duccius[?] - inscriptions, notably a tombstone of Lucius Duccius Rufinus at York[2] (http://museums.ncl.ac.uk/archive/arma/contents/iconog/tombston/cent1/uk/york/duccius.htm)
... to make the gyro fall over.)
The axis of the gyroscope in the Dynabee is fixed to the spinning mass and it rests in a little groove inside the wrist exerciser ...